Karyopharm Therapeutics Inc.'s selinexor, in combination with currently available treatments, showed high durable response rates in an ongoing phase 1b/2 study to treat multiple myeloma.
The company presented the early results at the American Society of Hematology 2017 annual meeting in Atlanta.
The STOMP study is evaluating selinexor and low-dose dexamethasone in combination with either Takeda Pharmaceutical Co. Ltd.'s Velcade or Celgene Corp. Pomalyst or Revlimid, as well as Janssen Biotech Inc.'s Darzalex, for treating patients with heavily pretreated multiple myeloma.
For the Velcade combination, the overall response rate in the proteasome inhibitor-naive or relapsed patient population was 84%. The median progression-free survival, or PFS, was more than 13 months. In the overall study population, 63% of patients saw a reduction in their disease, and patients taking the combination lived for a median of 9 months while keeping the disease at bay.
In the Pomalyst combination, overall response rate was 63% for the Pomalyst-naive and Revlimid-relapsed or -refractory patient group, with 11.6 months of median progression-free survival. The overall study population had a 56% overall response rate and a median progression-free survival of 11.6 months.
The Revlimid combination demonstrated a 92% overall response rate in the Revlimid-naive patient group. The overall response rate for the overall study population was 81%. However, both patient groups did not reach the median progression-free survival.
Lastly, in the Darzalex combination, the Darzalex-naive patient group's overall response rate was 83%, while the overall study population's overall response rate was 63%. Four of the nine patients in this study arm are still on treatment, Karyopharm said.
Karyopharm is evaluating selinexor in additional studies, including multiple studies in combination with one or more approved therapies in a variety of tumor types.